Chaeles a



(No Moel.) f

C. A. BAKER.

PILTBRING COMPOUND.

No. 286,370. Patented Oct, 9, 1883.

Inzfenor.

N4 FEYERS. Pwnrwgnpher, wmingm, n.6.

UNITED STATES ,PATENT EEicEO onannEs A. BAKER., on NEW Youn, n. r.

FILTERlNe-COMPOUND..

SPECIFICATION forming .part of Letters Patent No. 286,370, dated October9, 18.83.

` Application tiled 4July 5,1883. No model.)

To @ZZ whom/'it may concern:

Be it known that I, CEiARLEs A. BAKER, a citizen of the United States,residing at the city of New York, in the county of New York and State ofNew York, have inventednew and usefui Improvements in FilteringCompounds, of' which the following is aspecificacome-the tendencies ofthe latter to become an impervious mass when used alone for a filter. Inthis combinationthe bone-black serves also to solidify the in.c oinesiaand prevent it from impregnating the water or other filtrate; and theporosity of' the blocks is produced -in the operation of drying themunder a heat sufficient to evaporate the'water used in effecting theircombination. As a binding material to hold the particles coinpactlytogether and prevent cracking when dried, I use plaster-of'- pa'ris; andI may also use sand in the coinpound, when necessary to have the blocksextra porous; but my invention consists, broadly, in combining magnesiawith bone-black in such manner as to form a plastic mass for use in themanufacture of porous filtering-blocks. The blocks may be used in anysuitable filtering apparatus or device, and I have shown in theaccompanying drawings one form of :filter4 in which my articialbone-black blocks may be used.

In the production ofthe artificial bone-black blocks, I take bone-blackand magnesia in a finely-p owdered state and mix them thoroughlytogether and with water sufficient to render the compound plastic, inwhich I may also use a small quantity of -plaster-of-paris and sand whenrequired. The proportions of these articles will be governed accordingto thedegree of porosity required in the block to suit differy entliquids. The following proportions will give good results: bone-black,twenty parts, by weight; magnesia, seventy-miie parts, by

q weight; plaster-of-paris, one part, by weight.

This compound will produce a porous block of artificial bone-blacl;,inwhich the magnesia is made more solid and less soluble, and 'willproduce a filtering-block which will be a most perfect clarifier,absorbent, and strainer, rendering the `filtrate pure. y

It will be understood that the articles comin a dry condition and the`water then added to produce a plastic mass, which is placed in suitablemolds. The molds are then placed in a suitable drying-room andthoroughly dried under a moderate heat of, say, about 120 Fahrenheit. Itis in this drying operation that the blocks become porous by the actionofthe nlagnesia being in large proportion, while the bone-black rendersthe magnesia less soluble and gives it more solidity.y The porous blocksmay be thus vproduced and form a perfect lter; but I prefer to useplaster-of-paris in the compound to give a binding action to theparticles composing the mass, and to prevent cracking in drying". Inplace of plaster-oi'- paris, any other binding material may be used,such as Portland cement, Src. v

' In applyingthe blocks for filtering I place one or more of them into asuitable vesselor apparatus in-such manner that the liquid to befiltered must percolate through the same.

In case severa-lblocks are used the joints between them should be closedby plaster-of'- paris, or other suitable material.

In the form of filter shown in the drawings, the usual filteringsubstaiices--such as charcoal, gravel, and ne sand-are used in differ-'ent layers, and upon these my porous artitlcial bone-blackfiltering-blocks, a., are placed, with a layer of gravel, sand, or otherarticle that will allow the, water to pass through it and to hold theporous blocks down in place.

The blocks may be of any suitable form and size to suit the filter, andshould be placed llatwise within the filter. removed and replaced by newones, when desired, at little expense. They may be laid in single ordouble layers.

rI he filtering layers of charcoal, gravel, and sand, are separated bysuitable fabric.

The drawinglrepresentfs a vertical section of'a filter, showing themanner of' using my filtering-blocks, in whicha are the blocks; b, alayer of sand; c, a layer of gravel; and d, the charcoal-these fil- Iheymay be easily IOO e c 1 l esame tering substances being separated bysuitable fabric, e; and f is a layer of gravel or equivalent materialplaced upon the blocks to hold them in place within the Vessel7 whichmay be of any suitable construction7 and is pro- `vided with a cock7 g,communicating vwith the black, magnesia7 and a binding material7substantially as described.

4. A filtering-block formed of bone-black7 magnesia, and a bindingmaterial7 substan- 2o tially as hereinbefore described. y

5. A filtering compound consisting of bone black, magnesia,plaster-of-paris, and sand7 substantially as described.

6. A filtering-block formed of bone-black7 25 magnesia,plast-er-of-paris7 and sand, substan tial'ly as described. Y

f In testimony whereof Illa've hereunto set my hand in the presence oftwo subscribing witnesses.

CHARLES A. BAKER.

Vitnesses:

THEO. K. Torr-ULL, I J. W'. HAMILTON JorrNsoN.

